Opponents said they worry the requirement could make it difficult for many to vote, especially the elderly, minorities and students. They also said the ID requirement could eliminate same-day voter registration and be expensive and difficult to enforce.

"The only thing this amendment can possibly accomplish is to deny an eligible voter the right to vote," Sen. Dave Tomassoni, DFL-Chisholm, said.

"We are truly not targeting any class of voters except those voters not eligible to vote or doing so illegally," said Sen. Scott Newman, R-Hutchinson, the bill author.

The governor cannot veto or approve the bill because it would be a constitutional amendment, but Gov. Mark Dayton has said he opposes it.

The proposed amendment would create provisional balloting, which allows people without an ID to vote, but return to a clerk's office within a set time period to show proper identification.

If voters approve the amendment, the next Legislature would hammer out the details. The requirement would be effective during elections occurring on and after Nov. 5, 2013, Newman said.